| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Bolivar | 1 | 12,191 | 10,803 | 1.64% | 1,482 | 8 | City |
| Humansville | 2 | 949 | 913 | 0.74% | 760 | 1 | City |
| Fair Play | 3 | 456 | 435 | 0.88% | 1,068 | 0 | City |
| Morrisville | 4 | 401 | 383 | 0.75% | 621 | 1 | Town |
| Halfway | 5 | 153 | 147 | 0.66% | 76 | 2 | Village |
| Flemington | 6 | 116 | 110 | 0.87% | 350 | 0 | Village |
| Aldrich | 7 | 69 | 66 | 0% | 483 | 0 | Village |
Bolivar is the largest city in Polk County, with a population of 12,191.
Aldrich is the smallest city in Polk County, with a population of 69.
There are 7 cities in Polk County, Missouri.